The present invention relates to an automated solution injection-discharge system which automatically injects a dialysate into a patient""s peritoneal cavity and discharges the dialysate after the appointed time. In addition, the present invention relates to an automated peritoneal dialysis system (APDS) which employs the above-mentioned automated solution injection-discharge system.
Dialytic treatment has advantages such as (1) medical expenses are inexpensive, (2) the patient does not require frequent outpatient treatment, and (3) the patient can easily return to society. As a result, medical facilities in Japan have increasingly introduced dialytic treatment.
In continuous ambulatory peritoneal dialysis (CAPD), a patient can easily replace the dialysate at home at moderate cost. Many peritoneal dialytic patients have recently received CAPD treatment. In this treatment, however, a patient has to exchange bags several times, desorb connectors, and open and close a clamp (a closing gear) every day, which is troublesome to the patient.
An operating mistake by a patient, especially by a sight-or hand-impaired patient, may contaminate the connector of the dialytic system. Moreover, a user may make mistakes in injecting and discharging.
Based on the weak points above, the peritoneal dialysis system with automatic operation has been developed and improved. A conventional peritoneal dialysis system has adopted a method in which a dialysate is injected, by the head drop, into a patient""s peritoneal cavity and discharged from a patient""s peritoneal cavity.
This type of peritoneal dialysis system is relatively simple in structure. Moreover, the mechanism is safe and gentle to the living body because the dialysate is injected and discharged by gravitation.
However, the head drop mechanism has some demerits in that the patient must maintain a fixed posture, and the system is relatively large in size.
As a countermeasure against these, a roller pump is used to inject and discharge a solution in the peritoneal dialysis system. A system with a roller pump requires no head drop. However, there is a possibility that dialysate may be excessively injected into a patient because the roller pump may rotate without reference to the prescribed volume of solution. Another possibility is that the peritoneum may be damaged if the roller pump automatically sucks when a small amount of dialysate remains in the peritoneal cavity. The conventional solution injection-discharge system has merits and demerits as mentioned above. Other demerits are as f follows. First, the system is large in size and expensive because a load cell weighs the filled and drained volumes of solution.
Second, the control system is complicated and expensive because each closing gear, which is installed on each conduit connected between a dialysate bag, a drain bag, a patient""s peritoneal catheter, a warming gear, and a reservoir for compounding and warming a solution, operates separately.
The first object of the present invention is to provide a compact, simple-structured, and user-friendly automated solution injection-discharge system ensuring safe operation of injected and discharged solution. Especially when the automated solution injection-discharge system is used as an APDS system to supply and discharge a dialysate and a patient""s drain, the object is to provide an automated solution injection-discharge system (1) which is free of contamination and operation mistakes, and (2) which can accurately control the injected dialysate volume and the discharged dwell solution volume even when a patient does not maintain a fixed posture while replacing the solution.
The second object of the present invention is to provide an automated peritoneal dialysis system (hereinafter referred to as APDS) which operates in a set order and lessens manual operations for replacing a dialysate. The third object is to provide a compact, simple-structured, and low-cost APDS.
An automated solution injection-discharge system according to the invention comprise: (1) a chamber which is provided with a gas opening to introduce or exhaust a gas at one end of the chamber, and a solution opening to suck or discharge a solution at the other end; (2) a diaphragm installed in the chamber, which divides the chamber into a room with the gas opening and a room with the solution opening, for sucking a solution into the chamber or discharging a solution from the chamber by introducing or exhausting a gas through the gas opening; (3) a driving device which drives the diaphragm; (4) a measuring device which detects the volume of a solution sucked into or discharged from the chamber, and the volume of air sucked into or exhausted from the chamber; and(5) an air-pressure sensor which detects the pressure in a tube to supply or suck air into the chamber; wherein, by sucking a gas into the chamber through the gas opening, the diaphragm is inverted to the side of the gas opening to suck a solution into the chamber, and by introducing a gas into the chamber through the gas opening, the diaphragm is inverted to the side of the solution opening to discharge a solution from the chamber.
The driving device is provided with any one of the driving device such as an air cylinder, a piston and cylinder, and a flexible bag.
The volume of the air cylinder is 1.4 to 2.0 times the volume of the chamber.
The measuring device is a position detecting sensor which is installed near the driving device.
The automated solution injection-discharge system is used for an automated peritoneal dialysis system.
An automated peritoneal dialysis system accordong to the invention comprises: a dialysate container; a reservoir to contain a dialysate before it is injected into a patient""s peritoneal cavity; a drain container to contain a drain from a patient""s peritoneal cavity;an automated solution injection-discharge system to suck and supply dialysate and drain; said automated solution injection-discharge system being provided with the following (1) to (5):(1) a chamber which is provided with a gas opening to introduce and exhaust a gas at one end of the chamber, and a solution opening to suck or discharge a solution at the other end; (2) a diaphragm installed in the chamber, which divides the chamber into a room with the gas opening and a room with the solution opening for sucking a solution into the chamber or discharges a solution from the chamber by introducing or exhausting a gas through the gas opening; (3) a driving device to drive the diaphragm; (4) a measuring device which detects the volume of solution sucked or discharged by the chamber, and the volume of gas sucked into or exhausted from the chamber; and(5) an air-pressure sensor which detects the pressure in a tube to supply or suck a gas into the chamber; a manifold connected to the automated solution injection-discharge system; plural conduits connected between the manifold and the containers: and conduit swiching device to open and close the conduits.
An automated peritoneal dialysis system according to the invention comprises:a dialysate container; a reservoir to contain a dialysate before it is injected into a patient""s peritoneal cavity; a drain container to contain a drain from a patient""s peritoneal cavity; and an automated solution injection-discharge system which sucks and supplies dialysate and drain; said automated solution injection-discharge system being provided with:a piston and a cylinder; a measuring means which measures the volume of solution sucked into or discharged from the cylinder, and the volume of air sucked into or exhausted from the cylinder; and an air-pressure sensor which detects the pressure in a tube to introduce or suck an air into the cylinder; a manifold which is connected to the automated solution injection-discharge system; plural conduits connected between the manifold and the containers; and conduit swiching device to open and close the conduits.
An automated peritoneal dialysis system according to the invention comprises:a dialysate container; a reservoir to contain a dialysate before it is injected into a patient""s peritoneal cavity; a drain container to contain a drain from a patient""s peritoneal cavity; an automated solution injection-discharge system which sucks and supplies dialysate and drain; said automated solution injection-discharge system being provided with:a flexible bag; a measuring means which detects the volume of solution sucked into or discharged from the flexible bag, and the volume of gas sucked into or discharged from the flexible bag; and an air-pressure sensor which detects the pressure in a tube to supply or introduce air into the flexible bag; a manifold connected to the automated solution injection-discharge system; plural conduits connected between the manifold and the containers; and conduit closing gears to open and close the conduits.
The plural dialysate containers, each container having a dialysate of different density are provided with.
The peritoneal catheter in the patient and/or at least a part of the conduit connected to the catheter are made from a flexible thin film.
The automated solution injection-discharge system is aseptically structured.
The pressure sensor detects the volume of dwell solution discharged so that the pressure in the peritoneal cavity is not sufficiently negative to damage a living body.
The speed of movement of the air cylinder piston is 10 to 200 ml/min, preferably 150 ml/min, for discharging a solution from a patient""s peritoneal cavity, and the speed of injection of a solution is 20 to 400 ml/min, preferably 300 ml/min.
The conduit swiching device comprises:a rotating shaft; and swiching device which are provided with: an interlocking cam installed on the rotating shaft; a thrust device which moves up and down with the rotation of the interlocking cam; and a cradle which receives the head of the thrust device; wherein the number of rotating shafts is more few than the number of conduit swiching means.
The conduit swiching device are equipped with plural rotating shafts, said shafts having two or three conduit swiching means.
The conduit swiching means are provided with two rotating shafts, of which the first rotating shaft has three sets of conduit swiching means, and the second rotating shaft has two sets of conduit swiching means.
The three sets of conduit swiching neans on the first rotating shaft have a phase difference of 120 degrees, and the two sets of conduit swiching means on the second rotating shaft have a phase difference of 120 to 180 degrees.
An automated peritoneal dialysis system according to the invention comprises:a dialysate container; a reservoir to contain a dialysate before it is injected into a patient""s peritoneal cavity; a drain container to contain a drain from a patient""s peritoneal cavity; an automated solution injection-discharge system which sucks and supplies dialysate and drain; a manifold connected to the automated solution injection-discharge system; plural conduits connected between the manifold and the containers and the patient; and a conduit swiching device to open and close the conduits; said conduit swiching device being equipped with swiching means which are driven by rotating shafts, the number of which is more few than the number of swiching means.
An automated peritoneal dialysis system according to the invention comprises: a dialysate container; a reservoir to contain a dialysate before it is injected into a patient""s peritoneal cavity; a drain container to contain a drain from a patient""s peritoneal cavity; an automated solution injection-discharge system which sucks and supplies dialysate and drain; a manifold which is connected to the automated solution injection-discharge system; plural conduits which connect between the manifold and the containers and the patient; a conduit swiching device to open and close the conduit; a measuring means which detects the volume of solution sucked into or discharged from a chamber, and the volume of air sucked into or exhausted from the chamber; and a pressure sensor which detects the pressure in a tube to introduce air into the chamber; said pressure sensor detecting the volume of dwell solution discharged so that the pressure in the peritoneal cavity is not sufficiently negative to damage a living body.